The present invention relates to a storage controller, data processing method and a computer program product.
Lately, disk array apparatuses have been used as storage systems for managing large amounts of data. A disk array apparatus, having a number of disk drives arranged in arrays, provides host systems with storage resources, which together form a RAID (Redundant Arrays of Independent Inexpensive Disks) structure. A storage area network (SAN) environment using Fibre Channel (FC) protocol as an interface for network-connecting the host systems and the disk array apparatus has become popular. The disk array apparatus connected to the host systems via the SAN is equipped with channel control units for receiving block access requests. Each channel control unit includes a plurality of Fibre Channel control processors for controlling the Fibre Channel interfaces used between the channel control unit and the host systems; and a plurality of channel processors for processing I/O requests from the host systems. As mentioned in Japanese Patent Laid-Open (Kokai) Publication No. 1997-160889, it is essential for a system equipped with a plurality of processors to control and equalize the loads on the respective processors to enhance the system processing efficiency.